The B-21 is progressing to roll out and first flight, as the Air Force wrestles with how many to buy.
The first B-21 stealth bomber will roll out of its California factory in early 2022 and make its first flight a few months later. The second, nonflying test model is also in assembly. Contracts should be coming soon for constructing hangars and maintenance facilities at operating bases. Despite the COVID-19 pandemic, the project appears to be on track. But how many Raiders will be builtâand at what paceâremains an open question.
The first Raider is âreally starting to look like a bomber,â said Randall G. Walden, director of the Air Forceâs Rapid Capabilities Office (RCO), which manages the highly secretive program, in an exclusive interview with Air Force Magazine.
The B-21 will come out in the open for engine runs, taxi tests, and other necessary ground checks at Northrop Grummanâs Palmdale, Calif., plant in early 2022. The first flight should follow several months later, Walden said. That first flight will be a short, 36-mile hop from Palmdale to Edwards Air Force Base, Calif. Once there, the 420th Flight Test Squadron will put the bomber to extensive aerial tests.
Earlier forecasts of a December 2021 first flight were a best-case scenario, Walden said. The development team now thinks mid-2022 is âa good bet.â

The second airplane is âreally more about ⌠the overall structural capability,â according to Walden. âWeâll go in and bend it, weâll test it to its limits, [and] make sure that the design and the manufacturing and the production line makes sense.â
Lessons learned in building the first airplaneâwhich Walden noted is not yet in final assemblyâare paying off on No. 2, he said. Assembly is âgoing much fasterâ than on the first one, and the program is seeing âvery high percentages of efficiency, as compared to No. 1.â
The progress on Nos. 1 and 2 is making room for more aircraft on the line, Walden mentioned, although the actual production capacity is a secret. There will be more than two test aircraft, but he declined to say how many. The B-21 contract calls for 21 initial aircraft in five lots.
âWe want to make sure weâre efficiently using test ranges, and one way to do that is to have multiple test aircraft available,â Walden noted. In 2015, Air Force officials said the first aircraft will be âusable assets,â suggesting some test airplanes will be later reconfigured into operational machines.
Time of the first flight will be âdata driven,â Walden insisted, meaning it will take place only when the aircraft is ready, rather than according to the calendar.
Bomber pilots and maintainers are embedded with the development team to provide insights and feedback on every aspect of the design, said Walden. âBuilding a future stealth bomber is a complicated endeavor, and weâre going to do everything in our power to make sure we do that right.â
Long Haul
The B-21 will be able to carry both conventional and nuclear payloads. âWe are building the airplane to have the access, range, and payload that is needed for the future high-end fight ⌠as characterized by a highly contested environment,â he said. The goal is to âhold any target at risk,â no matter how well defended. The aircraft must be âeffective for a very long time as the threat evolves,â he said, and its open architecture will allow frequent and seamless, âalmost … plug-and-playâ updates to the B-21âs capabilities.
Structured from the outset to drive down risk, rather than âinventing on schedule,â Walden described exhaustive testing both on the ground and in an airborne avionics laboratory, hosted aboard a business jet-class airplane. The flying lab will shake out sensors and other electronics to ensure they work individually and cooperatively before being installed in an actual B-21. The concept is similar to the concept of the Cooperative Avionics Test Bedânicknamed âCATbirdââused by Lockheed Martin in developing avionics, apertures, and sensors for the F-35.
âNot having to have the actual test aircraft up there, but a flight test variant with the same systems, does help on the integration aspects on the article itself,â Walden reported. âIn the last few months we did another successful end-to-end demonstration … to further mature that hardware and software, and itâs working quite well.â
When itâs time to âpower-on and operate these systems on the actual B-21 test article,â Walden said, the team will have âa lot of confidence and a lot of experienceâ with them.
Although the Raider is still in development, âwe view the B-21 as really a production program, not so much just a test program,â Walden explained. To the extent possible, the test aircraft are being built on production tooling, using robots, particularly for composite structures, but also with âtouch labor.â
To reduce development risk, the B-21 was conceived to be more about integration than invention, Walden explained. âWe have not lost sight of the fact that we have to integrate software and hardware. … We are doing that today.â
The Air Force is ânot getting something experimentalâ in the B-21, former service acquisition chief Will Roper said in a January exit interview with Aviation Week and Space Technology.
The B-21 âis being designed for production innovation, for maintainability and sustainability ⌠and those are the things Iâve tracked the most,â Roper said. The first flight is âin no way, shape or form ⌠just to prove out the flight sciences. ⌠All of that has been worked concurrently.â
The bomber should transition to production at scale âvery quickly,â Roper said.
âStringent nuclear requirementsâ mean the program wonât move as fast as it might, though. âWe are going to try to speed up the nuclear certification process,â Roper told Aviation Week. âUntil itâs demonstrated and approved, we simply canât put the nationâs nuclear deterrent at risk in an experimental prototyping effort.â
Major Redesign
There are likely to be development surprises on the B-21, âjust like any otherâ aircraft development program, Walden said. Additional test infrastructure was added early on to ensure the program doesnât bog down when they occur, he said. Rep. Rob Wittman (R-Va.), a member of the House Armed Services Committee, revealed in 2018 that the B-21 was having problems with airflow and thrust, related to the bomberâs inlet geometry, serpentine air ducts, and exhausts. Walden acknowledged those challenges, and said theyâd required a âmajor redesign.â
âThis is a good example of some of those surprises,â Walden said, adding that itâs typical for a complex new aircraft program to have âinstalled engine inlet/exhaust integration issues that have to be resolved.â
Walden said the issueâthe details of which he would not discloseâis now well understood. Changes have been made, and âit looks like we have solved it, and we are moving forward with that final design.â
There were no hiccups in the program attributable to the takeover of engine maker Pratt & Whitney from United Technologies Corp. to Raytheon Technologies, Walden asserted. The change was âtransparent,â he said, adding that Northrop is doing a good job managing its subcontractors, and âin this particular case … the engine manufacturers.â

âSand in Our Gearsâ
The COVID-19 pandemic âthrew sand in our gears,â Walden said. Challenges continue, and âweâre still not out of it.â
The RCO and Northrop worked with suppliers to ensure that the flow of parts to Palmdale wasnât badly disrupted. Essential travel was re-sequenced to âwork around state and local restrictionsâ and quarantine requirements, Walden said. The changes seem to be âworking quite well,â he added. The program is also making increased use of secure video teleconferencing where possible. âI think weâve got a new norm, like everybody else out there,â he observed.
At least one opportunity presented itself due to the pandemic. Boeing had to slash orders from Spirit AeroSystems for 737 work due to the slowdown in air travel and ongoing 737 MAX grounding. Spirit and Northrop proposed shifting many of those aerostructures’ workers to the B-21, and the RCO agreed.
âWe knew that having additional folks that would [otherwise] be laid off, would help us,â Walden said. A combination of additional âtooling, funding, and the manufacturing really did make the B-21 line more efficient.â Other pandemic-inspired efficiency efforts have been undertaken, but none as âdramaticâ as the Spirit move, which Walden said proved âa huge benefit.â
Generally, âweâve compensatedâ for COVID delays, Walden said, and they should pose no significant risk to first flight.
The RCO Way
The RCO specializes in quick-turnaround, super-secret projects. Walden said heâs not collected any metrics about how much time has been saved managing a major project like the B-21 âthe RCO way,â and he admits some have pressured the program to âgo faster and build.â
But, âYouâve got to get the systems engineering right,â he said. Development will take âas much time ⌠as it takes.â
As head of the RCO, Walden has direct access to the Chief of Staff, the only person authorized to make changes to the program, and that minimizes the decision time when choices must be made. âWe are more streamlined and less bureaucratic,â he said. âTime delays with staffing documents is minimized.â
Circulating reports among layers of staff at the USAF and the Office of the Secretary of Defense levels might normally take âmonths on end,â but the RCO can do it in weeks. âIf I can cut that time in half, thatâs huge. If I can cut it by a tenth, thatâs [still] huge.â
The B-21 employs digital tools, but not to the extent envisioned by the Air Force in its push for âdigital engineering,â which employs digital models to work out design and engineering challenges before hardware is physically built.
The project has applied computer-aided design and maintainers try out procedures in a virtual setting, Walden said. But âweâre absolutely lookingâ at how digital twinning and other advanced design techniques could be brought to bear on the program. These techniques could be inserted âon a continuum,â he said, âIf it is going to save time, and dollars.â
Likewise, Walden said, artificial intelligence (AI) is not included among B-21 baseline features, but could be incorporated over time. The B-21 was intended to be an âoptionally mannedâ system, the Air Force said in 2015. âWe are looking for opportunitiesâ to insert AI, noting that itâs important to understand just what that means. The terms AI and machine learning tend to be used âvery loosely,â he said.
âWe are not solely focused on just trying to put AI [in], where âif you donât have AI, youâre nothing,ââ Walden explained. When âthe algorithms are written, we may be able to put it on there, and [it will] be least costly … and not impact any schedule.â
How Many Raiders?
The Air Force says its future force structure requires at least 220 bombers. The service plans to retire the B-1B and B-2 bombers, necking down to just the B-21 and the B-52. There are only 76 B-52s.
But Walden maintains that the goal is to produce âat least 100â bombers, and âright now, no oneâs told us to make that change.â
Can the program build more than 100? âAbsolutely,â he said, but there is a âmaximumâ that can be turned out by one production line. If more are desired, Walden needs âsome lead timeâ to add tooling and workers. âYouâve got to factor that in early enoughâ to anticipate when the planes must be delivered.
He added that while thereâs been âa lot of conversation of buying more,â thereâs âalso been conversations about buying less.â
The future 220-bomber force could include other aircraft. Gen. Timothy M. Ray, head of Air Force Global Strike Command, told Air Force Magazine last year that his command may buy some âattritable aircraftâ for long-range strike.
The B-21 production strategy, as it stands, âmeets the needâ stated by Air Force Global Strike Command (AFGSC), Walden said.
Pentagon and congressional leaders need to understand the limits of B-21 production capacity âso when asked if we [can] do more, we have an answer for the leadership.â

Courtesy graphic/Northrop Grumman
Beddown Moves
A âbeddown industry dayâ for the B-21 at Ellsworth Air Force Base, S.D., in January showed âwe are on [the] pathâ to delivering jets, Walden said. The event launched the process of building the facilities needed to receive and operate the aircraft.
The Air Force announced in 2018 that todayâs bomber basesâEllsworth, Dyess Air Force Base, Texas, and Whiteman Air Force Base, Mo.âwill become B-21 bases when they transition from the B-1 and B-2, respectively. AFGSCâs âBomber Vectorâ said the B-1 and B-2 would retire in the 2031-2036 time frame. More recent comments suggest it will be sooner.
Walden said the combination of hangar and weapons facilities on the base would cost âroughly a billion dollars … over the next handful of years,â with â$300 million through FY22 alone.â Walden noted that Congress included $10 million to fund a low-observables maintenance hangar at Ellsworth in the fiscal 21 budget; an item that was on USAFâs âunfunded prioritiesâ list.
More industry days hosted by the Air Force and the Army Corps of Engineers are coming, he said.
Walden reiterated the Air Forceâs standard line that the B-21 will be available for duty in âthe mid-2020s.â However, Lt. Gen. James C. Dawkins, deputy chief of staff for strategic deterrence and nuclear integration, said on Jan. 14 that the B-21 will start coming online in 2027 or 2028.
During a Heritage Foundation event to discuss the Long-Range Standoff weapon, which will equip the B-52 and B-21, Dawkins said the bomber leg of the nuclear triad would be comprised âof B-52s and B-2s, and in another six or seven years, the B-21.â
The program has âstuck toâ saying the first B-21 will be delivered in the mid-2020s, Walden noted. We donât see any delay … or accelerationâ to that.
The 80 Percent Solution
Walden has said heâs a fan of the â80 percent solution;â wherein a new system meets the majority of operator requirements without expending enormous effort and money to obtain extra performance that may only be marginally useful.
The goal of the B-21 is not to âget the perfect aircraft,â he said. The bomber has been designed to be improved as the threat changes. To try to âget it all done up frontâ means âyou ⌠never achieve a production-ready platform,â he asserted.
That said, âI believe weâre doing much better than âthe 80 percent solution.ââ He added that, â80 percent on a new platform is infinitely better than legacy platforms that canât do the job.â The B-21 now being built is â100 percent of what we want it to be.â